Raking classifier



Aug. 4, 1953 c. H. SCOTT RAKING CLASSIFIER 9 Sheets-Sheet l priginalFiled April 20, 1949 INVENTOR! ,=!CHARLES HAROLD seerr, 3, I BY ATTORNEY:Aug. 4, 1953 c. H. SCOTT 2,647,631

" RAKiNG cL s s IFi'ER ori in-a1 Filed April 20. 1949 i 9 Sheets-$113INVENTOR: CHARLES HAROLD SCOTT,

BY 0.3!... MM

ATTORNEY 1953 c. H. SCOTT 2,647,631

RAKING CLASSIFIER Original Filed April 20, 1949 4 9 sheets-Shea sFlG.ll.

a INVENTOR: CHARLES HAROLD SCOTT,

ATTORNEY Original Filed April 20, 1943 c. H. 'sco'rT RAKING CLASSIEIERc. H. SCOTT BAKING CLASSI'FIER Aug. 4, 1953 9 Sheetsr-S heet" 5 OriginalFiled April 20,- 1949' FIG. l3.

lNVENTORi m; ATTORNEY Aug. 4, 1953 c. H. SCOTT BAKING CLA$SIFIEROriginal Filed April 20, 1949 FIG. I6.

9 Sheets-Sheet '6 INVENTOR: CHARLES HAROLD SCOTT,

ATTORNEY Aug. 4, 1953 c. H. SCOTT 3 RAKIN CLASSIFIER Original FiledApril 20, 1949 9 Sheets-Sheet '7 INVENTOR:

QHARLES HAROLD SCOT T ATTORNEY Aug. 4, 1953.. c. H. sc'r'r ,647

RAKING cLAssmmR v Original Filed A ri'rzo, 1949 9 s'heits -snee't s NINVENTOR: CHARLES HAROLD SCOTT,

BY WNW.

ATTORNEY Aug. 4, 1953 c. H. S'CO'TT 2,

RAKING CLAssIFiER Original Filed April 20, 1949 9 Sheets-Sheet 9 IO N 'Wji i:

n ATTORNEY Patented Aug. 4, 1953 RAKIN G CLASSIFIER Charles HaroldScott, South Norwalk, Conn, as-

signor to The Dorr Company, Stamford, Conn., a corporation of DelawareContinuation of application Serial No. 88,619, April 20, 1949. Thisapplication December 28, 1951, Serial No. 263,892

23 Claims. (Cl. 209-462) This invention relates to classifiers of thereciprocating rake type adapted to treat a bath of suspended solids forthe purpose of fractionating the solids according to size so that anoverflow contains suspended solids below a certain or predetermined sizecalled fines, while the fraction of larger sized solids areprogressively emerged and delivered from the classifier as sands. Suchclassifiers comprise a tank having an inclined bottom or deck alongwhich longitudinally-extending rake structures are adapted to havereciprocating strokes imparted to them. During a stroke up along theinclined deck, settled solids are conveyed by the rakes. To that end therake structures are lowermost and adjacent the deck during up-deckstrokes and are uppermost and away from the deck during down-deckstrokes. Thus, the rake structures are adapted to be raised and loweredduring the transition between strokes.

So the general problem in the design of such a classifier is to devisean acceptable and satisfactory drive for moving the raking bladesupwardly along the inclined bottom of the tank, raising the rakingblades, moving them through a return stroke while elevated from the tankbottom, descending the blades to the tank bottom, and then through theirupward stroke again.

One such drive arrangement is shown in Patent No. 2,437,760 grantedMarch 16, 1948, to Frank L. Graner and the present applicant,application for which was filed on April 14, 1945, and was accordedSerial No. 588,360. In that patent there is shown a shaft extendinglongitudinally of the tank and mounted from the tank for rocking oroscillating about its longitudinal axis with a dwell between eachstroke. This rockable or oscillant shaft is provided with crossarmspivotally mounted on the shaft and spaced apart longitudinally along theshaft. With this arrangement, means are provided for rocking the shaftand meanwhile moving the cross-arms about their pivots. The free ends ofthe crossarms are provided with hangers which support a rake structurefrom the free ends of the arms on one side of the rockable shaft andanother rake structure from the free ends on the other side. Thearrangement is such that when one rake structure is moving adjacent thetank bottom on an up-stroke, the other rake structure is elevated and ispassing through its return stroke.

The pivoted cross-arms of the rockable shaft present difiiculties indevising dependable motivatine m so 11 s an obieet of this invention tomake use of the rockable shaft but to fix the cross-arms on that shaftso that they are not pivoted and then provide new and novel means forsupporting the rake structures from the nonpivoted arms as well as newand novel means for reciprocating the rake structures from these arms.

A feature of the present invention relates to the introduction oflongitudinally-extending slideway constructions positioned between theouter ends of the arms and the hangers for the rake structures. Thisslideway construction is preferably of a character which whilesupporting the hangers for longitudinal reciprocation permits them tohave slight angular movement about a longitudinally-extending pintleaxis as the rockable arms are raised and lowered.

Another object is to devise a satisfactory drive-head construction foraccomplishing both the rocking movement of the shaft and its fixedcross-arms as well as the proper longitudinal reciprocable movements ofthe rake structure. The drive-head embodies a rotary mechanism of acomposite type for converting its rotary motion into (1) the rockingmotion of the rockable shaft and (2) the reciprocating motion of therake structures.

A further object of the invention is to devise connecting means betweenthe fixed cross-arms and the rake structure hung therefrom so that therake structures can be reciprocated while they are supported from thecross-arms that rock unitarily with the rockable shaft and yet which maybe held relatively stationary for a particular interval of time. Thus,the general problem of the design of such a classifier is to devise anacceptable and satisfactory drive for moving each rake structurecyclically forward along the inclined bottom of the tank; raising suchstructure while in its forward position, moving such raised structurethrough a return stroke elevated from the tank bottom to a rearwardposition, and lastly, lowering the rake structure to the tank bottompreparatory to its starting position preparatory to its next forwardraking stroke of the next cycle. The pair of rake structures hung fromthe rockable shaft operate in balanced relationship, namely, when one isin forward raised position, the other is in lowered rearward position,and vice versa.

In such a classifier it is advantageous, particularly at a time ofabnormal overload of feed to the classifier, or of starting up of theloaded classifier after a period of rest, to make provision for liftingthe rear portion of the rockable shaft and its rake structures from thenormal low positions. To satisfy such requirement, a construction hasbeen designed whereby the forward end of the rockable shaft is mountedfor limited pivotal movement about a transversely-extending axis and atthe same time the rear end of the shaft can be elevated should operatingrequirements make that desirable. The novelty of the new constructionresides in the details whereby this is accomplished.

Some of the features of this invention include:

(1) The rockable shaft with its straight parallelly extending guidewayslocated at the outer ends of the cross-arms fixed on the shaft, fromwhich guideways there are supported depending hangers for the rakestructures whereby as the rake structures are longitudinally moved, theytravel in straight paths paralleling the axis of the rockable shaft; (2)a novel form of drivehead mechanism; (3) a novel mounting of thedrive-head mechanism with respect to the tank and a novel mode ofemploying that mechanism for supporting the rockable shaft; and (4) thedrive-head mechanism with a housing or cage supported for limitedmovement about an axis transverse to the classifier and provided with abearing for the forward end of the rockable shaft located so that theaxis of the shaft is higher than the axis of the drive mechanism.

The foregoing and several novel features of construction are embodied inthe new form of apparatus constituting the basis of the inventionhereof. Other new and important features of construction will bemanifest from the detailed description which follows:

There is herein disclosed the best embodiment of the invention now knownto me and that embodiment has been chosen for the purpose ofillustration of the invention hereof. It will be described preciselywithout attempt to refer to modifications or equivalents which, however,can be used while still falling within the ambit of this invention. Thenucleus and bounds of this invention are set forth in the appendingclaims but possibly in less precise language than that employed in thebody of the specification.

The embodiment chosen for use in exemplification is illustrated in theaccompanying drawings constituting a part of this specification, inwhich:

Fig. 1 is a plan view of a classifier embodying the invention hereof.

Figs. 2 and 2 when brought into alignment collectively provide avertical longitudinal sectional view of the classifier as the sameappears when taken on a vertical plane indicated by the dot and 'dashline 22 of Fig. 1, looking in the direction of the arrows. The deep endof the classifier is the rear overflow portion thereof while the shallowend is the front or sands-discharge portion thereof.

Fig. 3 is an elevational side view indicating by full lines thearrangement and embodiment of important novel features of constructionby which rake structures indicated by dotted lines are coordinatedlyraised or lowered or in timed relationship moved longitudinally inrearward or forward direction as the case may be.

Fig. 4 is a view looking downwardly at the construction of Fig. 3 in thedirection of arrow 4. In Figs. 3 and 4 certain parts of the housing ofthe drive-head have been broken away so that certain features ofconstruction adapted therefor may be indicated.

Fig. 5 is a longitudinal view, partially section,

of a slideway construction which is employed at the outer end at eachset of arms connected to and extending from the rockable shaft. Thisview also shows a portion of a depending member of the slidewayconstruction by and from which a section of the rake structure deriveslongitudinal slidable support from a set of rocker arms.

Fig. 6 is a transverse sectional view taken on vertical plane indicatedby the broken dot and dash line 6-6 of Fig. 5, looking in the directionof the arrows.

Figs. 7 to 10 inclusive are detailed views of a depending member that isincluded in the slideway construction of Figs. 5 and 6 and from whichthe rake structure derives carrying support. Of the figures justmentioned, Fig. 10 is a cross-sectional view taken on a vertical planeindicated by the dot and dash line l0i0 of Fig. 9.

Fig. 11 is a front elevational view partially in section and of whichcertain parts have been broken away.

Figs. 12 12 and 12 collectively constitute a longitudinallyandtransversely-extending sectional view of the drive head. This is a viewtaken as on a plane indicated by the dot and dash line l2-l2 of Fig. 2or by dot and dash line l2--I2 of Fig. 13.

Fig. 12* shows an outer broken off portion of a support tube of 12 Fig.12 illustrates the rear end of a drive link of which the forward end ismounted on the outer end of a crank arm of 12 and of which link the rearend is mounted on a wrist pin on a rake structure to which the linkcorresponds.

Fig. 13 is a vertical view of the drive-head looking in a rearwarddirection toward the front of the classifier. In this view some of theparts of the housing structure and of the mechanism of the drive-headare broken away to show more clearly the arrangement of certain movableparts constituting the assembly of coordinated actuated members of thedrive-head.

Fig. 14 is a vertical longitudinal sectional view illustrating portionsof the drive-head and while at the same time indicating the location offorward supporting bearings provided for receiving the front end of therockable or oscillant shaft of the tiltable rocker.

Fig. 15 is a detail indicating how a roller-carrying arm which isconnected to the front end of the rockable shaft can yield or break uponabnormal conditions being encountered by the shaft or by the partscarried therefrom.

Fig. 16 is a view looking rearwardly at a turnable grooved cam of thedrive-head mechanism.

Fig. 17 is a sectional View looking in an upward direction of theforward grooved portion of the cam. This view is taken as on the dot anddash line ll-l1 of Fig. 16 looking in the direction of the arrows.

Fig. 18 is a development of the grooved portion of the cam of Fig. 16.

Fig. 19 is a partial plan view in the general vicinity of the rearmostportion of the rockable shaft.

Figs. 20 and 21 are vertical detailed views, Fig. 20 being a view takenas on a vertical longitudinal plane indicated by the dot and dash line20-20 of Fig. 19 looking in the direction of the arrows, and Fig. 21being an upright transverse view looking at the parts of Fig. 20 in thedirection of the arrow 2 1.

Figs. 22 and 23 respectively provide a vertical longitudinal viewpartially broken away and an upstanding rear view partially broken awayof the liftable rear bearing and hydraulic mechanism for lifting thesame and thereby the rear end of the rockable shaft, Fig. 22 being aview taken on a vertically and longitudinally extending plane indicatedby the dot and dash line 22-22 of Fig. 23 looking in the direction ofthe arrows and Fig. 23 being an upright view looking forwardly at thestructure of Fig. 22 and in the direction of arrow 23.

Fig. 24 is a perspective view of a housing or cage member employed in amodified form of drive-head mechanism shown in Fig. 25.

Fig. 25 is a perspective view of a modified form of drive-headmechanism.

Reference is now made to the drawings in detail:

The cdnstruction illustrated as embodying the invention hereof includes(1) a deep end tank having an upwardly inclined bottom or deck; (2) apair of longitudinally-extending rake structures arranged side by sideand provided with transverse raking blades; (3) a rocker of rigidconstruction embodying a rockable longitudinal shaft portion and rockerarms extending laterally in opposite directions from the shaft; (4) alongitudinally-extending slideway construction provided at and for theouter end of each rocker arm or set of rocker arms and having alongitudinal slidable member providing part of a depending carriersupport for corresponding portion of a rake structure; (5) a frontsupport bearing for the forward end of the rockable shaft provided inand by a housing constituting part of the drive-head mechanism nextreferred to; (6) a drive-head mechanism supported with respect to thefront end of the tank so as to have slight angular movement about atransverse axial line and which embodies the housing structure as wellas motivated means having a mechanical element for imparting spacedperiodic rocking movement to the shaft and also mechanical elements forimparting spaced periodic longitudinal back and forth movements; (7) aliftable rear bearing member that receives and carries the rear endextension or lower support shaft of the rockable shaft El; (8) a supportfor the elevating means hereinafter referred to; and (9) an elevatingmeans carried by said support and provided for raising and lowering theliftable rear bearing member.

The several parts listed above will be described in detail under therespective headings designated therefor.

Classifier tank The classifier tank is designated as ll]; means as at 9is provided for feeding and delivering into the tank a liquid-solidssuspension or mixture of metallurgical pulp containing suspended solidsto the classifier.

The tank Ii) has a sloping bottom or inclined deck H from which thererise side walls 12 and I3 and at the deep end an end wall M in the formof a bent plate having a lower section l5 extending at right angles tothe inclined deck and a vertically-extending section I6 providing anoverflow edge H at elevation lower than that of the edge portions of theside walls and lower than that of the sands-discharge end or forwardedge I8 of the inclined deck H. The overflow edge I! of the end wallserves as a weir determining the normal operative overflow elevation forliquid with suspended fine solids therein leaving the tank, and therebydetermining the normal operative surface level for the liquid within thetank. An overflow receiving launder or out-- now discharge means isprovided at H! from which liquid rid of heavy solids passes from thetank to the place of disposal. Raked or classified coarser solids orsands pass as relatively dewatered solids from the forward upper end ofthe inclined deck. The tank [0 can be made of sheet metal properlystiffened but it will be understood that it can be made of any suitablema terial depending upon the particular type of employment. Thereextends upwardly from and along the inclined deck a centrally locatedlongitudinally-extending partitioning rib 2| whereby there are providedright and left trough-like receiving sections as 22 and 23 whereinalternate raking operations are carried out by respective rakestructures 24 and 25.

Rake structures Each set of rake structures includes sets oflongitudinals or stringers as 26 and longitudinally spaced transverseraking blades as 21 that are fixedly secured to the longitudinals. Theseblades extend downwardly to regions below the set of longitudinals bywhich they are carried. Each rake structure has upwardly-extendin fromthe longitudinal stringers carrier plates or hangers as 28 whereby theremay be connected thereto depending tang portions 5| of a longitudinalslidable member of the longitudinal slideway construction 32 hereinafterreferred to. In this connection reference is made to the slidewayconstruction 32 as shown in Figs. 5 and 6 and to the detailed membershown in Fig. '7.

Rocker construction The rocker construction is shown in Figs. 3 and 4 byfull lines in a manner to indicate its functioning position with respectto rake structures indicated by dot and dash lines. Those figures canwell be employed in conjunction with the slideway construction showingof Figs. 5 and 6 and the front end showing of Fig. 11. The showing ofFigs. 3 and 4 are provided whereby certain novel features of a built-uprocker construction can be later forcibly brought out by referencethereto. This rocker construction is of rigid construction and includeslongitudinally-spaced forwardly disposed and rearwardly disposed rockerarm members 62 each of which includes a shaft section 6-5 from whichthere extend in opposite directions fork-shaped sets of rocker arms63--63. As constructed the tiltable rocker embodies a built-up shaftwhich includes in serial arrangement a supported front end shaft section64, sometimes referred to as a pivot shaft, a first shaft-providingsection 65 from which the rocker arms 63 extend, an intermediate tubularsection 66, sometimes referred to as a torque tube, a secondshaft-providing section 65, and lower support shaft 61, sometimesreferred to as the rear shaft extension 61 which is supported in a rearrocker shaft bearing N. This longitudinally-extending rocker or rockableshaft is collectively designated as 6| and from the laterally branchingforkshaped rocker arms 6363, sometimes called cross-arms, there aresupported through the medium of pivot members as 36 in the outer ends ofthe forked arms mentioned, the slideway hanger construction 32 of Figs.5 and 6.

slideway hanger construction The slideway hanger constructionconstitutes an important feature of this invention as it was designedwhereby an oscillant rigid arm rocker construction can be employed andwhereby longitudinal reciprocating movements can be imparted to the rakestructures in directions paralleling the longitudinal axis of theoscillant shaft, and it is therefore in order to describe thisconstruction at this time. Said slideway hanger construction, thusgenerally designated as 32, constitutes a rake-carrying structure whichis interposed between the outer ends of each pair of fork-shaped rockerarms 63 and a corresponding portion of the rake structure which iscarried therefrom. The outer ends of the arms are bored so as to receivethe pivot members 36- referred to and which pivot members in turnreceive and through the medium thereof support apertured trunnions 35-35of a longitudinally-extending body member 33 of the slideway hangerconstruction 32.

This slideway hanger construction 32 is shown in general arrangement anddetail in Figs. to inclusive. It embodies the body member 33 justreferred to. The body member has longitudinally apertured trunnions35-35 which are mounted in the pivot members 36 provided to receivethem. The openings in the trunnions are in alignment with openingsprovided in the pivot members 36. The body member 33 has a crossheadcover 47 detachably secured thereto as by bolts. Each body member 33 hasparallel supporting guideways 40 upon which there are mountedlongitudinally movable slidable members 4| that include sho members 42having underlying anti-friction bearing members 43 resting upon andslidably engaging guideways 40. The slidable member 4| also includescross-head caps 45 topped by anti-friction guide blocks 43 disposed forengaging the underside of the crosshead cover 41. The slideway hangerconstruction has a cross-head member 48 (see Figs. 7 to 11) providedwith lateral trunnions 50 mounted in the slidable members 4| so that atang portion 5| of the member 48 depends from the trunnion supportedportions 5050 thereof. This crosshead member 48 has a body portion 49from which the lateral trunnions 50 extend. These trunnions are receivedand maintained in circular bearings provided therefor by the shoes 42and caps 45 thereof and which collectively constitute parts of theslidable members 4|. The caps 45 are secured in place relative to theshoes 42 as by screws 44. The cross-head member 48 has its tang portion5| extending from the trunnion supported body 49 thereof to a regionbelow the body member 33 of the slideway construction. This dependingtang 5I has a series of bolt-receiving openings 52 whereby the lower endof the tang can be clamped and fixedly secured as by bolts 53 to theupper ends of the upwardly and inwardly inclined carrier plates 28 of aportion of the rake structure. Filler or spacer pieces 29 indicated inFigs. 5 and 6 can be interposed between the depending tang portion onthe one hand and the upwardly and inwardli inclined carrier plates onthe other hand. Since each cross-head guide is mounted through themedium of the longitudinal apertured trunnions 35-35 there are providedmeans by which, as the rocker 6| is tilted about its inclinedlongitudinal axis in one direction, one of the rake structures issuspendingly supported in low position therefor for longitudinal forwardmovement as by the up-deck stroke while the other rake structure issuspendingly supported in raised position therefor for longitudinalrearward non-raking movement preparatory to subsequent lowering into lowforward raking position.

According to this new form of slideway hanger construction 32 it will benoted that there is permitted a pivotal movement of the slidewayconstruction about the trunnion axis mentioned as the rocker arms areswung up or down, as the case may be, and also there is provision for alimited relative pivotal movement as between the depending cross-head 48and the slidable member 4| because the lateral trunnions 50 of thecrosshead are mounted in circular bearings provided in and by the shoes42 and the caps 45.

The slideway construction as employed has an upward and forwardinclination in general longitudinal direction. Accordingly, one of thepivot members 36 is located at the high forward end thereof and theother pivot member is located at the low rear end thereof. To theforward pivot member there is secured and carried an upstanding oil cup30 for supplying lubricant through the apertured trunnion of the bodymember 53 for lubricated slideway and the lower pivot member is providedwith a depending oil receptacle 3| for receiving lubrication passingfrom the slideway construction through the apertured portion of thetrunnion member whereby it can be collected in the latter receptacle.This oil receptacle is preferably provided with a valve-controlleddischarge means leading therefrom. By the oil supply cup 30 and thedepending oil receptacle 3| the movable elements of the slideway can belubricated by the means of support therefor and can readily bemaintained lubricated.

In the Figs. 5 and 6, there is also shown a wrist pin 55 carried inwrist pin supports 56. These wrist pin supports have cylindrical bearingmembers 57 for receiving the outer ends of the wrist pin and thesebearing members 5'I have welded thereto longitudinally-extending members58 angle shaped in cross-section and secured to upwardly inclined rakehangers 2328 as through the medium of bolts 59. The rear end 54 of oneof the connecting rods I23 or I24, as the case may be, is mounted on thewrist pin 55 and as the a1 paratus functions the connecting rod impartsthe forward or rearward longitudinal movement to the rake structure towhich it corresponds.

Drive-head mechanism The drive-head mechanism or drive unit assembly, asit may be called, is illustrated by Figs. 12 to 18 inclusive. Its useand place of employment is further exemplified by reference to Figs. 1to 4 inclusive and also to Fig. 11. In this connection one should bearin mind that Fig. 11 is a view of the forward end of the classifierlooking in a rearward direction and that the drive-head mechanism is inthe foreground.

The important features and parts shown in the views of Figs. 12 to 14comprehend the gear housing or cage embodying right and left sidesections I0| and I02 connected into a gear casing unit by bolts I03extending through flange portions |04|04 thereof.

This housing provides longitudinally aligned bearings 93 and 94, seeFig. 14, for receiving the pivot shaft 64 which functions as a front endsection of the rocker shaft 6|. In connection with the foregoing alsosee Figs. 3 and 4.

Support tubes 95 and 96 are secured to and extend from the housingsections IIlI and I 02. The support tubes 95 and 96 are in turnsupported in aligned but transversely spaced pedestal bearings 91 and98. The pedestal bearings 91 and 98 are n turn supported on the frontend portion of the side walls of the tank through the medium of spacerblocks 99 and all are secured in place by bolts I (see Fig. 11). Thepedestal bearings 91 and 98 establish a transverselyandhorizontallyextending axial line about which the drive-head mechanismcan have a limited angular movement and. which angular movement isrequisite when the rear end of the rocker parts carried thereby are tobe lifted or raised.

The drive-head mechanism embodies gearin including (1) a motor actuatedtransverse pinion shaft I having thereupon pinions I01 and I08 which aregears of small diameter and preferably of the herringbone type; (2)large driven gears I09 and I I0 are arranged so that the herringbonetype of teeth thereof are in meshing driven engagement with the pinionsor small gears I01 and I08; (3) a cylindrical cam I06 disposed betweenand connected to the large driven gears I09 and H0 so as to beconcentric therewith; and (4) crank shafts III and H2 having flangedinner ends H3 and II connected to, concentric with and driven by thelarge gears I09 and H0; these shafts are turnably mounted within andextend outwardly through anti-friction bearings H5 and H6 provided inand carried by bearing rings II! and I I8 which are secured as by boltsI I 9 and I2 whereby to constitute part of the housing 90. The result ofthe construction just described is such that the crank pins I 2I and I22of the crank shafts I II and II2 are located outside of the casing orhousing 90. These crank pins are arranged 180 apart. The drive-headmechanism also actuates rearwardly-extending connecting rods I23 and I24of which the forward ends I25 and I26 have driven connection with thecrank pins I2I and I22 of the crank shafts III or II 2, as the case maybe, while the rear ends of the connectin rods (each rear end beingdesignated 54) have driving connection to the rake structures throughthe medium of the respective wrist pins 55 mounted in the wrist pinsupports 56 carried by the rake structures to which a particularconnecting rod corresponds.

The crank shaft III, the driven gear I09, the cylindrical cam I06, thedriven gear '0 and the crank shaft II2 are thus serially arranged andare connected in transverse axial alignment into a composite rotarystructure that is mounted for turning movement as imparted thereto by Do gears I1 and I08 on the actuated drive pinion shaft I05, but so as tobe restrained against any substantial play in transverse directionbecause of the construction of the anti-friction bearings H5 and II6 assupported in and carried by t transversely spaced crank shaft bearingrings I I1 and H8 provided for receiving and holding the anti-frictionbearings H5 and H6. Tapered D1118 I30 function as positioning membersfor assuring proper alignment of the side sections IOI and I0 as andwhen they are screwed together by the several bolts I03.

A requirement of the housing 90 is such that while it is supported forpermitting slight angular movement thereto about a transverse axis asdetermined by the support tubes 95 and 96 which are mounted in the sideor pedestal bearings 91 or roller-carrying arm 10 teeth of the largedrive gears I09 and H0 on the other hand.

With respect to the two small pinions I01 and. I08 on pinion shaft I05and the two large drive gears I09 and H0 of the composite assemblyreferred to, it will be noted that they are preferably provided ascoordinatedly disposed sets of gears of herringbone type of constructionwhereby the right and left hand type of pinions I0? and I08 respectivelymesh with left and right hand typ of drive gears I09 and H0, thusassuring an arrangement in which there is attained a tendency for theset of gears and set of pinions to constantly remain in an arrangementaccording to which balanced driving of the large gears I 09 and H0 frompinions I01 and I08 is attained and whereby there is avoided anytendency for substantial bodily movement in an axial direction of thepinion shaft I05 even though the anti-friction bearings I21 and I23provided for the pinion shaft I05 are non-fixedly mounted in alignedopenings I3I and I 32 provided therefor in and by the housing sectionsWI and I02.

It is in order to digress for the moment for the purpose of explainingthat the drive pinion shaft I05 is actuated from a motor which isoutside of the classifier through a speed reducing andpower-transmission means 8 embodying belting I 50 driven from the rotorof the motor and a shaft pulley I55 mounted on a shaft I52. (In thisconnection see Figs. 1, 11 and 12 The shaft extends into the supporttube and is mounted in an anti-friction bearing I5I which in turn isinternally mounted within the outer end portion of the support tube 95.The inner end of the shaft I52 is splined and there is a spline sleeveI63 that provides a drive connection between the inner splined end ofshaft I52 and a splined end of pinion shaft I05.

The outer end portions of the support tube are provided with oil-sealingcaps secured thereto, namely, there is a sealing cap I53 for the supporttube 95 and sealing cap I54 for the support tube 95.

Reverting to the cylindrical cam I06, it will be noted that it has agrooved profile I33 for receiving a cam-actuated roller I34. This rolleris turnably mounted at the low swinging end I35 of a roller-carrying armI 36 which forms a separable connection between the cam and the rockableshaft 6| and is carried at and yieldably secured to the pivot shaft 64constituting a forward extension of the shaft 6I. This camroller-carrying arm I36 is normally firmly, although yieldably, seatedagainst resisting portions I3'II3'I provided on the pivot shaft 64 atthe underside thereof and the arm is normally held quite rigidly inplace through the medium of a pair of eyebolt type of tension rodsI38I38 continuously maintained under tension by compression springsI39I39 respectively surrounding the rods. These eyebolts pass upwardlythrough a portion of the pivot shaft. The lower ends of said springsrest in depressed seat portions I 40--I40 in the upper surface portionof the pivot shaft and the upper ends of said springs engage the underside of a spreading plate forming an upper spring seat member I4I thatisheld in spring compressing position by nuts I42I42 that are adjustablypositioned on the upper portion of the tension rods referred to. Thelower ends of these tension rods have eyeportions I43 for receiving apin I44 which passes through a section I45 of the upper end of the I36.Depressed portions HIS-I46 at the upper end of this roller-carrying armforcibly engage the resisting portions I3'I 131 at the underside of thepivot shaft. In the form shown the resisting portions I3I-I 31 areprovided by longitudinally-extending projections resembling parallelribs with curved underfaces. These ribs are transversely spaced withrespect to each other and the curved faces are received in thecooperatively depressed portions I46 just referred to.

In Fig. 13 the parts just referred to are shown in a position which theroller-carrying arm I36 normally occupies during non-overload operatingcondition.

In Fig. 15 there is shown a position typifying that which theroller-carrying arm can occupy relative to the pivot shaft should anabnormal overload or obstructing condition be encountered. This positionindicates what is termed a break or yielded or separated position forthe arm. As soon as overload operating conditions have been overcome thecompression springs [39-439 force the separable roller-carrying arm I36into normal position therefor.

There has already been indicated that the rocker 60 embodies therockable shaft 6| and rocker arms 63 which are fixedly and rigidlyconnected as parts thereof. There has also been brought out how therocker arms extend outwardly from the rockable shaft and thereforefunction periodically to raise and to lower the rake structure asrequired through the medium of longitudinal slideway constructions as 32and also whereby because of the latter the rake structures are supportedso as to be moved in forward and rearward directions as part of cyclicpaths through which each rake structure travels during the successiveoperative movements thereof.

There has also been described the drive-head mechanism which comprises acylindrical cam I06 that constitutes part of a driven rotary memberwhich is coordinatedly disposed for actuating the roller of aroller-carrying arm that is connected to a forward end portion of therockable shaft, namely, to the forward pivot shaft section 46 thereofwhereby to impart the requisite rocking or oscillating movements to therocker shaft.

There have also been mentioned crank shafts which have been described asconstituting part of the rotary member whereby through the medium ofconnecting rods connected to the ends of the crank shafts and to therespective rake structures the latter can be moved back and forth in theproper manner one with respect to the other.

It is believed, however, that amplification of the description of thecylindrical cam I06 which has a peripheral groove of 360 angular degreesand this mode of operation for performing the work required of it can befurther exemplified by reference to Figs. 16 to 18 inclusive hereof.

The cam I06 with its peripheral groove I33 is illustrated in Fig. 16which is a view looking in a rearward direction at the cam. In thisconnection it will be noted that Fig. 17 is a horizontal sectional Viewof the peripheral portion of the cam taken on a plane indicated by thedot and dash line I'II'I looking in an upward direction indicated by thearrows, and that Fig. 18 shows a development of the grooved profile I33of the cam.

As already pointed out and in connection with Figs. 12 to 14 inclusive,it will be seen how the pivot shaft 64 constituting the front end of therockable shaft 6|, the roller-carrying arm I38 and the roller I34 at thelower end of the arm (which roller enters the groove I33 of the cam)cooperatively function and from the preceding description it will beapparent.

(a) When the roller I34 is in the dwell section I of 70 angular degreesof the profiled groove that the right rake structure is held in lowforward raking position while being moved forwardly by the connectingrod provided between-the outer end of the right crank shaft and theright rake structure;

(b) When the roller I34 is in the reverse curved roller actuatingsection 2 of angular degrees of the profiled groove that the roller isthen being actuated to swing the rockable shaft 6| so as to elevate theright rake structure and to lower the left rake structure;

(0) When the roller I34 is in the roller dwell section 3 of 70 angulardegrees of the profiled roove that the left rake structure is then inits low forward raking position while being moved forwardly by theconnecting rod provided between the outer end of the left crank shaftand the left rake structure; and

(d) When the roller I34 is in the reverse curved roller actuated section4 of 110 angular degrees of the profiled groove that the roller is thenbeing actuated to swing the rocker shaft so as to elevate the left rakestructure and to lower the right rake structure to low position forforward raking operation when and While the roller is in dwell sectionI. Of course, it will be realized that when any one of the associatedright and left rake structures is in low raking position and is beingmoved forward by a crank and connecting rod mechanism correspondingthereto, the other rake structure is being moved rearwardly in highreturn or non-raking position therefor.

Liftable rear bearing member The bearing is provided for receiving andcarrying the rear end extension 6'! of the rocker shaft 6|. This rearend extension is sometimes referred to as the low support shaft of therocker. The liftable rear bearing H is indicated in Figs. 3 and 4. Itslocation with respect to the rear end of the rocker and other structurein the vicinity thereof and particularly with respect to supportingstructure for the elevating means hereinafter described is clear fromthe showing in Figs. 21 to 25.

The liftable bearing II derives its entire support through the medium ofthe elevating means and the latter in turn derives its support from astationary structure fixedly positioned with respect to the tank as willpresently appear.

Support for the elevating means (For location see Figs. 1 and 2 and fordetails see F g 21 to 25) lgs The support for the elevating means is ofa rigid construction and is afforded by a structure which includesupwardly-extending side members 86-86 fixedly positioned with respect tothe tank, a transverse tubular carrier 81 connected as by welding to theupper ends of the side members 86-85, short transversely spacedforwardly-extending members 88 having a weld connection to the tubularmember 81, an upper set of transversely spaced upwardly-extendingmembers 8989 which are secured to and rise from forwardly-extendingportions of 8888 and a horizontallyand transversely-extending top platemember I9 carried at and secured to the upper ends of members 8989. Theplate member I9 just referred to constitutes a. table top upon which abase 83 of a cylinder of the expansible and contractible lifting meansis fixedly secured in any suitable manner. The tubular cross-member 87also carries a set of transversely spaced blades that provide rearwardextensions 269 for supporting the set of depending members 2lll whichserve as means by which the forward end portion of the feed conduit 9derives its support.

Elevating means for rear bearing As to the means for raising or forlowering the elevatable rear bearing II for the rocker shaft 6|, this isprovided by 9. raising and lowering mechanism of a hydraulic type and iscollectively designated I4 and is carried by the support structure justdescribed. The hydraulic type of lifting means I4 referred to istypified by a construction embodying a liftable piston I5 located in acylinder I6 in which a rising or upstanding piston rod I8 of the pistonextends through a cap member 82 located at the upper end of thecylinder. The lower end of the cylinder I6 rests upon and is connectedto the base 83 which provides a lower head for the cylinder. Pressurefluid for actuating the piston may be supplied from any suitable sourceof liquid supply as through the medium of pipes 84 and 85 because offlow-paths provided in or by the cylinder base 83, the cylinder I6 andthe cylinder cap 82.

The liftable bearing II at and for the lower rear end shaft section 61of rockable shaft 6|, is supported from the liftable piston I5 throughthe medium of a liftable yoke or cross-head 'I'I carried on the upperend of the upstanding piston rod I8 of the piston I5, depending rods I3of eyebolt formation of which the upper ends of the rods 13 areadjustably carried by nuts 8i resting upon the lifting yoke and of whichthe low eye portions of the rods I3 receive and support lateraltrunnions 80 extending outwardly from the liftable bearing I I.

With respect to this rear bearing construction it is to be noted thatthere is preferably interposed a bushing between the rear end of thetiltable shaft and the supporting bearing 'Il therefor. It will also benoted that the cylinder and piston with piston rod extending upwardlytherefrom are disposed so that the centerline common thereto extends inupward direction approximately at right angles to the longitudinal axisof the rockable shaft when the latter is in its normal low position.

General In apparatus of the type disclosed where parts thereof requirelubrication, this may be accomplished either by oiling systems designedwhereby to supply oil therefor from a central location or oiling meansprovided at and for oiling individual bearings.

In apparatus where cranks or other moving parts are exposed it isadvisable to supply shielding means or guards to protect operators frominjury. Therefore, for practical operation it is preferable to have suchparts either enclosed or provided as by shield members.

'In the preferred form the gearing mechanisms have been enclosed in thehousing structure 90. Also in said preferred form there are indicatedshield members 3838 the location of which is shown in Figs. 1 and 2*,namely, in the region immediately ahead of the crank shafts and theconnecting rods which are connected thereto and driven therefrom.

The gear housing generally designated as 9|] is constructed so as toprovide inspection or access openings, as for example, for the housingside IUI there is normally sealed inspection opening I51 having aremovable cover plate I59 and for housing side section lll2 there is anormally sealed inspection opening I58 having a removable cover plateI69. Also at the top of the housing there is an access opening I6Inormally closed by removable housing cap I62.

The gear housing is split along a verticallyand longitudinally-extendingplane. The side sections IM and I02 thereof have shaft bearings thatmust be in proper alignment. The housing and gear thereof as maderequire that there be provision for ready, prompt and accurateassembling or re-assembling of the several parts embodied in thedrive-head mechanism, as for example, to assure the proper alignment orlocation of the several shaft bearing parts relative to each other. Tothat end there have been provided a plurality of tapering pins as I30which extend through contacting flanges of said side sections and whichpins can be relied upon for properly locating and for maintaining inproper location one housing side section relative to the other prior toand during the pulling of said sections together by the several boltsI03. Tapering pins and bolts may also be employed where other boltconnected parts are to be assembled or reassembled.

In Figs. 24 and 25 their is illustrated that which may be considered asa perspective view of a form of classifier construction modified as todetail as compared with the preferred form of classifier alreadydescribed. The modified form, however, embodies certain and in fact manyof the important novel characteristics features of the preferred form.

The perspective view of Fig. 25 may be described as a view looking atthe forward high end of the classifier in a direction slanting laterallyrearwardly and downwardly towards the classifier. In this figure thereis illustrated the forward or high sands-discharge end of the tank I0having an upwardly sloping bottom II and side walls I2 and I3 extendingupwardly therefrom. The tank has a centrally located partitioning rib 2|rising from the bottom. Rake structuers 24 and 25 are operativelydisposed respectively in the spaces between the partitioning rib and theside walls of the tank. Each rake structure has upwardlyandinwardly-extending hanger members or carrier plates 28. These carrierplates are supported from the outer ends 269-269 of forked arms 263 ofthe rocker construction 260 through the medium of slideway hangerconstructions 232 corresponding to the slideway hanger constructions 32previously described. In this connection it will also be noted that theslideway hanger constructions 32 have trunnions 35 at the ends thereofmounted in openings provided at and in the outer ends 269-269 of saidarms whereby the slideway hanger constructions can have slight angularmovement with respect to a longitudinal axis as the rake structures areraised or lowered because of a tilting movement imparted to the rockerconstruction.

The rocker construction 2611 includes a longitudinally-extending shaft26| providing a front end section or pintle shaft 264 that is mounted inbearings 293 and 294 of a cage or skeleton housing 290. This housing hasa transverselyextending supported bearing portion 295 which is mountedon and so as to have a slight bodily pivotal movement imparted theretoabout a transversely-extending motor driven shaft 252 which in turn ismounted in pedestal bearings 298 and 299. This motor driven shaft 252 isactuated from a motor, not shown, through the medium of a speed-reducingand power transmission mechanism embodying a belt 255 operable fordriving a large pulley 256 secured in place to a portion of the shaftthat extends into a region outside of the tank. The pedestal bearings298 and 299 rest upon spacer blocks 300 and 301 which are supported ontop flange portions of the corresponding sides [2 and I3 of the tank.The pedestal bearings and spacer blocks are secured in place on theflange portions of the tank as by bolts 302 and 303.

The transverse shaft 252 functions not only to support the cage orhousing 290, but also as a drive shaft to which there is secured a smalldrive pinion 307 which in turn is provided for imparting turningmovement to a large driven gear 309. This large driven gear 309constitutes part of a composite driven rotary unit 308 which embodies inserial arrangement crank shaft 3| at one end thereof, the large drivengear 309, the cylindrical cam 306 and a crank shaft 3H at the other endthereof, and all of which are connected in axial alignment. The crankshafts 3l0 and 3 have at the outer ends thereof crank arms as 3l2 fromwhich laterally extend crank pins 322 at the outer ends thereof. Thesecrank shafts are assembled in the composite rotary unit in a mannerwhereby the crank arms thereof are at 180 degrees relative to eachother.

The skeleton housing 290 has bearing portions 314 and 3 I 5 forreceiving the crank shafts of the rotary unit 308 and also employsbearings caps as 3 I 6 and 3 I l which are detachably secured in placeand which serve to maintain the rotary unit 308 in operative position.

The rotary unit 308 is so mounted in the skeleton housing so as toprevent any substantial play of the unit with respect to the housing indirections parallel to the motor driven shaft 252.

Also in connection with the foregoing, it will be noted that there areprovided collars 266 and 26'! disposed adjacent the pedestal bearings298 and 299 and so secured to the shaft 252 as to prevent anysubstantial play of said shaft in said bearings in a direction in whichthe shaft extends. Likewise, collars 210 and 21! are located on andsecured to the shaft 252 and are so disposed with respect to the bearingportion 295 of the skeleton housing whereby to prevent any substantialplay or movement of said cage or housing 290 in direction parallel tothe shaft 252.

It has heretofore been pointed out how the rocker construction generallydesignated as 260 embodies the oscillable longitudinally-extending shaft26! from which there extends the set of fork-shaped arms 263, namely, indirections as to the right and to the left from the shaft 26I and whichare so connected to the rocker shaft so as to move therewith when it isrocked.

It is also to be noted that in the structure as illustrated connectingrods as 324 are actuated from the crank pins 322 of the crank shaft andthat they are also essentially connected in suitable manner as through awrist pin, or the equivalent,, to the upwardlyand inwardly-inclined.

carrier plates 28 by and from which the rake structures are supportedfrom the longitudinallyextending slideway construction 232. It will benoted that the drive pinion 301 meshes with and imparts turning movementto the driven gear 309 of the composite construction whereby when saiddriven gear 309 turns there is imparted turning movement to both the camon the one hand and the associated crank shafts 3l0 on the other hand.The cam 306 has a profiled groove portion which embodies the structuraland functional characteristics of the cam 306 of the preferred form. Inthe modified form under consideration there is a cam actuated roller 334which is disposed within the profiled groove portion of the cam 306. Aroller-carrying arm 336 is connected to the shaft 269 so that as the camturns, it functions to impart in periodic order through the medium ofthe cam actuated roller 334 and the roller-carrying arm 336, therequisite movements to the shaft 264 and thereby to the rockerconstruction 260. The cam 306 is functionally positioned with respect tothe roller 334 and the roller-carrying arm 336 on the one hand and tothe crank shafts 310 and 3 on the other hand whereby there is obtainedthe coordinated raising and lowering movement of the rake structures bythe rocker construction as it is actuated and whereby the rakestructures are longitudinally moved in proper timed manner requisite fortheir proper operative movements. Also in connection with the modifiedform of Fig. 25 it will be apparent that the rocker construction 260 andthe longitudinal shaft 261 thereof-each of which is shown only as to theforward portion thereof can be provided with supporting and liftingmeans at the rear end thereof by the construction employed and shownwith respect to the preferred form as already described.

This application is a continuation of my patent application Serial No.88,619, filed April 20, 1949, now abandoned.

The embodiments of the invention in which an exclusive property orprivilege is claimed, are defined as follows.

I claim:

1. In a classifier having a tank with a sloping bottom for holding abath of suspended solids to be classified with a pair of balancedparallel complementally reciprocable longitudinal rake structures havinghangers for operating submergedly in the bath and with a rockablelongitudinal shaft from which the rake structures derive support;characterized by rigidly fixed arms on the shaft superposed above eachrake structure; elongated support means for reciprocably supporting eachhanger of the rake structure from the fixed arms on the correspondingside of the shaft, and motivating means connected to at least one hangerof each rake structure for its reciprocation irrespective of the rockedposition of the shaft and to the shaft for rocking it in timed relationto the reciprocating rake structure, one of said elongated support meansbeing held by each fixed arm and each support means including alongitudinal track member and a member slidable thereon with bothmembers parallel to the tank bottom.

2. Apparatus according to claim 1, wherein the application of themotivated means for the rake structures includes a crank for each rakestructure and drivingly connected to the rake structure to which itcorresponds.

3. Apparatus according to claim 1, wherein the 17 application of themotivated means to the shaft includes a grooved cam.

4. A classifier according to claim 1, with the addition of means forpivotally mounting one end portion of the shaft for limited movementabout a transverse pivotal axis so that if the end portion of the shaftis vertically moved the shaft carries with it the rake structures andcertain actuated members of the motivated means.

5. A classifier according to claim 1, with the addition of means forpivotally mounting a front end portion of the shaft for movement about ahorizontal transverse pivotal axis and means for raising the rear endportion of the shaft and consequently moving therewith rake structuresupported therefrom.

6.- A classifier according to claim 1, with the addition of meansproviding a housing having a longitudinal bearing for receiving andsupporting a front end portion of the rockable shaft, means forpivotally supporting said housing for limited movement about alongitudinal transverse axis radially spaced below the axis of saidrockable shaft, and means for lifting a rear end of the shaft andconsequently the ends of the rake structures from a normal operativepositiori therefor relative to the classifier bottom.

7. A classifier according to claim 1, having a housing providing abearing for receiving a forward end portion of the rockable shaft, meansfor supporting said housing with respect to the tank and for permittingpositionable movement of the housing about a transverse axial line, amotivated means embodying in coordinated arrangement a cam and a set ofright and left cranks and turnably supported in bearings by said housingwith an arm extending laterally from said rockable shaft and actuated bysaid cam and crank actuated means for each crank and in turn connectedfor imparting proper longitudinal movements to rake structurescorresponding thereto in a manner whereby there is obtained coordinatedtimed relationship of the rocked position of the shaft and thereciprocative movement of the rake structures.

8. A classifier having a tank with a sloping bottom for holding a bathof suspended solids to be classified while supported thereoverlongitudinally of the tank is a pair of balancedcomplementally-reciprocable rake structures having hangers supportedfrom a rockable shaft placed longitudinally of the tank whereby when theshaft rocks the rake structures rock with it, the improvement whichcomprises in combination rigidly fixed arms extending from each side ofthe shaft with one arm for each hanger, motordriven means forsimultaneously and independently applying in coordinated time relationrocking motion to the shaft and reciprocating motion to the rakestructures although in opposite balanced directions, and means betweeneach arm and its adjacent hanger for slidably and reciprocablysupporting each hanger from the arm from which it derives support.

9. A classifier having an inclined bottom tank for holding a bath ofsuspended solids to be classified into one fraction of suspended finesolids overfiowed from the deep end of the tank and one fraction ofcoarse solids emerged from the bath at the shallow end of the tank; apair of balanced complementally-reciprocable bladed rake-structureshaving hangers; a rockable shaft placed longitudinally of the tank; andimproved means for operating the rake-structures to stimulate suchclassification by moving submergedly each rake-structure forwardly alongthe incline of the tank in a sedimented-solids-raking stroke, then awayfrom the bottom whereby raked solids from which the rake-structure sodeparts can slip down along the bottom, then rearwardly in an elevatedliquid-agitating non-raking stroke, and finally toward the bottom topenetrate the layer of solids slipping down the incline of the bottom;which means comprise arms extending from each side of the shaft with onefor each hanger, motivating means having dual connections of which onereciprocates the rake-structures and the other rocks the shaft in timedrelation with the reciprocation of the rake-structures, andlongitudinally slidable support means paralleling the shaft whilelocated between each arm and its dependent hanger.

10. A classifier according to claim 9, wherein the arms have a main bodyportion parallel to the shaft and two-body-supporting connectionsextending generally laterally from the shaft and from the body portion.

11. A classifier according to claim 9, wherein the slidable supportmeans include a track supported from each arm upon which slides therespective hanger for that arm.

12. A classifier according to claim 9, wherein the arms have a main bodyportion parallel to the shaft and two body-supporting connectionsextending generally laterally from the shaft and from the body portion;and wherein the slidable supported from that arm.

13. A classifier having an inclined bottomed tank for holding a bath ofsuspended solids to be classified by hingered settlings into onefraction of suspended fine solids overfiowed from the deep end of thetank and one fraction of coarse solids emerged from the shallow end ofthe tank; a pair of balanced complementally-reciprocable bladedrake-structures having hangers; a rockable shaft placed longitudinallyof the tank; and improved means for submergedly moving eachrake-structure along a cyclic path that is substantially of oblong shapewith the long sides parallel the tank bottom and the short sidesextending toward and away from the tank bottom; which means comprisesarms extending from each side of the rockable shaft with one for eachhanger, longitudinally slidable support means for each hanger betweenthe hanger and its arm, motivating means, connections between themotivating means and a hanger of each rake-structure for reciprocatingthe rake-structures through the long sides of the path, and anotherconnection between the motivating means and the rockable shaft formoving the shaft together with its arms and the hangers of therake-structure through the short sides of the path.

14. A classifier having an inclined bottomed tank with a deep end and ashallow end for holding a bath of suspended solids to be classified; apair of balanced complementally-reciprocable bladed rake-structures; arockable shaft placed longitudinally of the tank from which therakestructures are supported; and improved means for submergedly movingeach rake-structure alon a cyclic path that is substantially of oblongshape with the long sides parallel the tank bottom and the short sidesextending toward and away from the tank bottom having a transverselyextending housing at the shallow end of the tank for supporting an endsection of the rockable shaft, a rotatable member in the housing, acrank carried by each end section of the rotatable memher but with thecranks diametrically spaced apart rotationally, connecting rod meansconnecting each crank with one rake-structure whereby therake-structures are moved along the long sides of their path, and meansfor moving the rake-structures alon the short sides of their pathcomprising a groove-bearing cam on the rotatable member, aroller-carrying arm supported from the rockable shaft engaging thecamgroove with that groove having two arm-dwelling sections interspersedbetween two arm-moving sections.

15. A classifier according to claim 14, wherein the roller-carryin armhas means between it and its rockable shaft that are,normally'nonyielding but which are yielding upon excessive loadpressures being transmitted therethrough to therockable shaft.

16. A classifier according to claim 14, wherein the roller-carrying armis normally maintained in rockable shaft actuating position by means ofspring-forced rods but which springs are con-- structed to yield uponimposition thereon of overload strains imparted thereto from therockable shaft.

1'7. A classifier according to claim 14, wherein the housing issupported from the tank by housing-tilting means tiltable about an axisthat is lower than the axis of the rockable shaft.

18. A classifier according to claim 14, wherein the housing is supportedfrom the tank by housing-tilting means tiltable about an axis that islower than the axis of the rockable shaft, and at the other end of thetank there is a support for the rockable shaft that is raisable andlowerable.

19. A classifier according to claim 14, wherein the axis about which thecranks rotate is lower than the axis of the rockable shaft.

20. A classifier according to claim 14, wherein the housing is supportedfrom the tank by housing-tilting means tiltable about an axis that islower than the axis of the rockable shaft as well as lower than the axisabout which the cranks rotate.

21. A classifier according to claim 14, wherein the cam is cylindricalwith a roller-actuating groove of 360 degrees along its marginal surfaceand has means for actuating it comprising a driven gear secured theretoat each end thereof with one crank being supported from each gear.

22. A classifier according to claim 14, wherein the housing comprises aclosed casing supporting the cam and cranks, and tubular means forReferences Cited in the file of this patent UNITED STATES PATENTS NameDate Scott et a1 Mar. 16, 1948 Number

